Lighting apparatus using organic light-emitting diode and method of fabricating the same

ABSTRACT

A lighting apparatus using an organic light-emitting diode and a method of fabricating the same are characterized in that an organic emissive material and a conductive film used as a cathode are deposited on the entire surface of a substrate, and then an organic emissive layer in a lighting area and contact areas becomes separated (disconnected or cut) by laser ablation, simultaneously with the formation of a contact hole for contact with an anode. Next, cathode contact and encapsulation processes are performed using an adhesive containing conductive particles and a metal film. This simplifies the fabrication process of the lighting apparatus without using an open mask (metal mask), which is a complicated tool, thus making it useful especially in roll-to-roll manufacturing.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 15/699,840 filed in United States of America onSep. 8, 2017, which claims the foreign priority benefit of KoreanApplication No. 10-2016-0166041, filed on Dec. 7, 2016, which are herebyincorporated by reference in their entirety for all purposes as if fullyset forth herein.

BACKGROUND Field of the Disclosure

The present disclosure relates to a lighting apparatus, and moreparticularly, to a lighting apparatus using an organic light-emittingdiode and a method of fabricating the same. Although the presentdisclosure is suitable for a wide scope of applications, it isparticularly suitable for a lighting apparatus using an organiclight-emitting diode, which allows for a simplified fabrication processby patterning the organic light-emitting diode without using an openmask, and a method of fabricating the same.

Description of the Background

Common lighting apparatuses currently being used include fluorescentlamps and incandescent lamps. The incandescent lamps have good colorrendering index (CRI) but very low energy efficiency, and thefluorescent lamps have good efficiency but low color rendering index andcontain mercury, posing environmental concerns.

A color rendering index, which indicates how accurately colors arereproduced, is a measure of the ability of a light source to reveal thecolor of an object faithfully in comparison with a reference lightsource. The CRI of sunlight is 100.

To resolve the problems with the conventional lighting apparatuses,light-emitting diodes (LEDs) are being proposed these days. However, theLEDs are made from inorganic emissive materials and have the highestluminous efficiency at blue wavelengths, and their luminous efficiencydecreases towards red wavelengths and green wavelengths, which is wherethe eye is most sensitive. Thus, when a red LED, a green LED, and a blueLED combine to emit white light, the luminous efficiency is low.

Lighting apparatuses using an organic light-emitting diode (OLED) arebeing developed as another alternative. A typical lighting apparatususing an OLED has an anode made of ITO over a glass substrate. Then, anorganic emissive layer and a cathode are formed, and a passivation layerand a laminate film are formed on top of them, followed by cover glasssubstrate attachment and encapsulation processes.

The deposition process of the organic emissive layer and the electrodes,which is the core process, is usually performed in high vacuumatmosphere, so it requires as many deposition chambers for maintaininghigh vacuum as there are thin films to be deposited.

In recent years, the use of flexible substrates instead of glasssubstrates is actively under research and development. In this case, aflexible substrate, usually wound on a roll, is installed onequipment—that is, roll-to-roll equipment for continuous feeding anddeposition. However, this causes to increase in the total number ofprocesses; especially, in the OLED process after the formation of theanode, the organic emissive layer, cathode, and passivation layer aredeposited using different open masks (i.e., metal masks) for thedifferent layers. After the deposition using open masks, a cleaningprocess is needed at every step, and the substrate and the open masksshould be aligned with each other. A misalignment may create shadow andpattern tolerance, thereby leading to defects.

SUMMARY OF THE DISCLOSURE

The present disclosure is directed to solving the above-describedproblems, and an aspect of the present disclosure is to provide alighting apparatus using an organic light-emitting diode, which allowsfor depositing an organic light-emitting diode without using an openmask (metal mask), and a method of fabricating the same.

These and other aspects and features of the present disclosure willbecome better understood with reference to the appended claims.

An exemplary aspect of the present disclosure provides a lightingapparatus using an organic light-emitting diode, including: a substratedivided into a lighting area and first and second contact areas, a firstelectrode on the substrate and a passivation layer on the firstelectrode.

The lighting apparatus using the organic light-emitting diode of theexemplary aspect of the present disclosure further includes an organicemissive layer and a second electrode on the entire surface of thesubstrate where the passivation layer is provided, a trench providedalong the edge of the lighting area and separating the organic emissivelayer in the lighting area and the organic emissive layer in the firstand second contact areas and a metal film attached over the substrate inthe lighting area and the second contact area.

The metal film may be attached over the substrate with an adhesive.

Another exemplary aspect of the present disclosure provides a method offabricating a lighting apparatus using an organic light-emitting diode,the method including: forming an organic emissive layer and a secondelectrode on the entire surface of the substrate where the passivationlayer is formed, forming a trench by removing the organic emissive layerand the second electrode from the edge of the lighting area, the trenchseparating the organic emissive layer in the lighting area and theorganic emissive layer in the first and second contact areas andattaching a metal film over the substrate in the lighting area and thesecond contact area, with an adhesive in between.

The first and second contact areas may be located outside the lightingarea.

The lighting apparatus may further include a first contact electrodeprovided in the first contact area and configured as an extension of thefirst electrode to the first contact area.

The lighting apparatus may further include a contact hole exposing thefirst contact electrode, provided by removing the organic emissive layerand second electrode in the first contact area.

The lighting apparatus may further include a conductive film in thecontact hole and over the second electrode in the first contact area,and electrically connected to the first contact electrode via thecontact hole.

The lighting apparatus may further include a second contact electrodeprovided in the second contact area and made of the metal film.

The lighting apparatus may further include a protective film provided onthe metal film in the lighting area.

The protective film may include an open hole exposing the second contactelectrode.

The adhesive may contain conductive particles, and the metal film may beelectrically connected to the second electrode by the conductiveparticles.

The conductive particles may be composed of nickel, carbon, or solderballs.

The organic emissive layer and the second electrode may be exposedthrough the sides of the substrate.

As described above, the lighting apparatus using an organiclight-emitting diode and the method of fabricating the same according toan exemplary aspect of the present disclosure may simplify thefabrication process of the lighting apparatus without using an open mask(metal mask), which is a complicated tool. Accordingly, it is possibleto reduce costs and simplify the processes and equipment, making themadaptable to a variety of models without additional cost.

Moreover, the lighting apparatus using an organic light-emitting diodeand the method of fabricating the same according to an exemplary aspectof the present disclosure allow for patterning organic light-emittingdiodes by using simple equipment, without using an open mask and othertools, making them useful for roll-to-roll manufacturing. This improvesproductivity while reducing manufacturing costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the disclosure and are incorporated in and constitute apart of this specification, illustrate exemplary aspects and togetherwith the description serve to explain the principles of the disclosure.

In the drawings:

FIG. 1 is a cross-sectional view exemplifying a lighting apparatus usingan organic light-emitting diode according to an exemplary aspect of thepresent disclosure;

FIG. 2 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to an exemplary aspect of thepresent disclosure;

FIG. 3 is a schematic cross-sectional view of the lighting apparatususing an organic light-emitting diode according to an exemplary aspectof the present disclosure, taken along line I-I′ of FIG. 2;

FIG. 4 is a cross-sectional view exemplifying the concept ofroll-to-roll equipment;

FIG. 5 is a flowchart sequentially showing a method of fabricating alighting apparatus using an organic light-emitting diode according to anexemplary aspect of the present disclosure;

FIG. 6 is a flowchart sequentially showing a method of fabricating alighting apparatus using an organic light-emitting diode according to acomparative example;

FIGS. 7A to 7G are plan views sequentially showing a method offabricating the lighting apparatus using an organic light-emittingdiode, shown in FIG. 2, according to an exemplary aspect of the presentdisclosure;

FIG. 8 is an enlarged view of a portion of the lighting area of FIG. 7B;

FIGS. 9A to 9F are cross-sectional views sequentially showing a methodof fabricating the lighting apparatus using an organic light-emittingdiode, shown in FIG. 3, according to an exemplary aspect of the presentdisclosure;

FIG. 10 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to another exemplary aspect ofthe present disclosure;

FIG. 11 is a schematic cross-sectional view of the lighting apparatususing an organic light-emitting diode according to another exemplaryaspect of the present disclosure, taken along line II-II′ of FIG. 10;

FIG. 12 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to still another exemplaryaspect of the present disclosure; and

FIG. 13 is a schematic cross-sectional view of the lighting apparatususing an organic light-emitting diode according to still anotherexemplary aspect of the present disclosure, taken along line III-III′ ofFIG. 12.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereinafter, a lighting apparatus using an organic light-emitting diodeand a method of fabricating the same according to a preferred aspect ofthe present disclosure will be described in sufficient detail to enablea person of ordinary skill in the art to readily practice thedisclosure.

Advantages and features of the present disclosure and methods ofaccomplishing the same may be understood more readily by reference tothe following detailed description of preferred aspects and theaccompanying drawings. The present disclosure may, however, be embodiedin many different forms and should not be construed as being limited tothe aspects set forth herein. Rather, these aspects are provided so thatthis disclosure will be thorough and complete and will fully convey theconcept of the disclosure to those skilled in the art, and the presentdisclosure will only be defined by the appended claims. Like numbersrefer to like elements throughout the specification. In the drawings,the sizes and relative sizes of layers and regions may be exaggeratedfor clarity.

It will be understood that when an element or a layer is referred to asbeing “on” or “above” another element or layer, it can be directly on orabove the other element or layer or intervening elements or layers maybe present. In contrast, when an element or a layer is referred to asbeing “directly on” or “directly above” another element or layer, thereare no intervening elements or layers present.

Spatially relative terms, such as “below”, “beneath”, “lower”, “above”,“upper”, and the like, may be used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation, in addition to theorientation depicted in the figures. For example, if an elementillustrated in the drawings is turned over, the element described to be“below” or “beneath” another element may be put “above” the otherelement. Accordingly, the exemplary wording “below” may include bothdirections corresponding to “below” and “above”.

The terms used in the present specification are used to describe exampleaspects of inventive concepts, and not to limit the inventive concepts.A singular form may include a plural form, unless otherwise defined. Theterms “comprise” and/or “comprising” specify the existence of mentionedcomponents, steps, operations and/or elements thereof, and do notexclude the existence or addition of one or more components, steps,operations and/or elements thereof.

FIG. 1 is a cross-sectional view exemplifying a lighting apparatus usingan organic light-emitting diode according to an exemplary aspect of thepresent disclosure.

FIG. 2 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to an exemplary aspect of thepresent disclosure.

FIG. 3 is a schematic cross-section view of the lighting apparatus usingan organic light-emitting diode according to an exemplary aspect of thepresent disclosure, taken along line I-I′ of FIG. 2.

The present disclosure provides a lighting apparatus using an organiclight-emitting diode made of organic material, rather than a lightingapparatus using an inorganic light-emitting diode made of inorganicmaterial.

An OLED made of organic emissive material has relatively good green andred emission efficiency compared to an inorganic light-emitting diode.Another advantage of the OLED is that it offers an improved colorrendering index because of its relatively broad red, green, and blueemission peak widths compared to the inorganic light-emitting diode,thereby generating light more close to sunlight.

In the description below, the lighting apparatus of the disclosure isdescribed as a lighting apparatus that flexibly bends, but the presentdisclosure may be applicable not only to a bendable lighting apparatus,but also to general lighting apparatuses that are not bendable.

Referring to FIGS. 1 to 3, a lighting apparatus 100 using an organiclight-emitting diode according to an exemplary aspect of the presentdisclosure may include an organic light-emitting diode part 101 wheresurface emission occurs, and a sealing part 102 that seals the organiclight-emitting diode part 101.

In this case, an external light extraction layer 145 for increasing hazemay be added to the bottom of the organic light-emitting diode part 101.

The external light extraction layer 145 is made of scattering particlesof TiO2, etc. dispersed in resin, and may be attached to the bottom of asubstrate 110 through an adhesive layer (not shown).

The organic light-emitting diode part 101 is made up of organiclight-emitting diodes placed on the substrate 101. In this case, aninternal light extraction layer 140 may be added between the substrate110 and the organic light-emitting diodes.

A planarization layer (not shown) may be added to the top of theinternal light extraction layer 140.

In this case, the substrate 110 may be divided into a lighting area EAthat actually emits light and sends it out, and contact areas (padareas) CA1 and CA2 that are electrically connected externally viacontact electrodes (pad electrodes) 127 and 128 and apply signals to thelighting area EA.

The contact areas CA1 and CA2 may be electrically connected externallyvia the contact electrodes 127 and 128 as they are not covered by ametal film 170, used as a sealing means, and/or a protective film 175.The first contact electrode 127 is electrically connected externally asit is exposed via a contact hole 114, and the second contact electrode128, formed from a portion of the metal film 170, may be electricallyconnected externally as it is not covered by the protective film 175. Inthis case, the first contact electrode 127 may be electrically connectedexternally through a conductive film such as ACF. However, the presentdisclosure is not limited to this, and an external electrical connectionmay be made through a given conductive layer that may be formed in thecontact hole 114.

The contact areas CA1 and CA2 may be located outside the lighting areaEA. For example, referring to FIG. 2, the contact areas CA1 and CA2 arelocated outside the upper part of the lighting area EA—that is, thefirst contact area CA1 may be located on the left side, and the secondcontact area CA2 may be located on the right side. This makes the moduleprocess easy. However, the present disclosure is not limited to thisconfiguration. The metal film 170 may be attached to the entire surfaceof the lighting area EA and second contact area CA2 of the substrate110, but not to the first contact area CA1, and the protective film 175may be attached to the entire surface of the lighting area EA of thesubstrate 110, but not to the contact areas CA1 and CA2.

An organic light-emitting diode is formed by a first electrode 116 and asecond electrode 126 positioned on the substrate 110 and an organicemissive layer 130 situated between the first and second electrodes 116and 126. In the lighting apparatus 100 of such a structure, when asignal is applied to the first electrode 116 and second electrode 126 ofthe organic light-emitting diode, the organic emissive layer 130produces and emits light through the lighting area EA.

The organic emissive layer 130 may be made up of light-emitting layersthat produce white light. For example, the organic emissive layer 130may be made up of blue, red, and green emitting layers or may be made upof a blue emitting layer and a yellow-green emitting layer stacked intandem. However, the organic emissive layer 130 of this disclosure isnot limited to the above-described structure, but various structures maybe applied to it.

The organic emissive layer 130 of this disclosure may further include anelectron injection layer and a hole injection layer that respectivelyinject electrons and holes into the emitting layers, an electrontransport layer and a hole transport layer that respectively transportthe injected electrons and holes to the emitting layers, and a chargegenerating layer that generates electric charges such as electrons andholes.

In this case, a trench T exposing a passivation layer 115 a may beformed by removing the organic emissive layer 130 and the secondelectrode 126 from the edge of the lighting area EA. The trench T isformed in the shape of a closed curve along the edge of the lightingarea EA, and functions to prevent moisture from penetrating the organicemissive layer 130 in the lighting area EA. Generally, polymers used asorganic emissive materials, when combined with moisture, degrade quicklyin their light-emitting characteristics, and the luminous efficiency ofthe organic emissive layer 130 therefore decreases. Especially when theorganic emissive layer 130 in the lighting apparatus 100 is partiallyexposed to the outside, moisture spreads into the lighting apparatus 100along the organic emissive layer 130, thereby lowering the luminousefficiency of the lighting apparatus 100. To overcome this, in thepresent disclosure, the trench T is formed along the edge of thelighting area EA, so as to prevent moisture from penetrating the organicemissive layer 130 in the lighting area EA of the lighting apparatus 100from which light is actually produced and emitted.

Referring to FIG. 2, the trench T of this disclosure may be formed inthe shape of an overall rectangular frame, but the present disclosure isnot limited to this shape.

The trench T may separate (break or cut) the organic emissive layer 130along the edge of the lighting area EA, thereby preventing moisture fromspreading into the lighting area EA along the organic emissive layer130. In particular, the trench T of this disclosure may simplify theprocess by laser ablation without using any photolithography process.

In this case, the first electrode 116 including the first contactelectrode 127 is positioned on the substrate 110 made of a transparentmaterial. The substrate 110, although may be made of a hard materialsuch as glass, may be made of a flexible material such as plastic tomake the lighting apparatus 100 bendable. Moreover, the presentdisclosure allows for roll-to-roll processing by using a flexibleplastic material as the substrate 110, thus facilitating a fabricationprocess of the lighting apparatus 100.

The first electrode 116 including the first contact electrode 127 isformed in the lighting area EA and the first contact area CA1, and maybe made of a transparent conductive material with a high work function.For example, in the present disclosure, the first electrode 116including the first contact electrode 127 may be made of a conductivematerial of tin oxide, such as ITO (indium tin oxide) or a conductivematerial of zinc oxide, such as IZO (indium zinc oxide), or may also bemade of a transparent conductive polymer.

The first electrode 116 may extend to the first contact area CA1 outsidethe lighting area EA and functions as the first contact electrode 127.

An auxiliary electrode 111 may be placed in the lighting area EA and thefirst contact area CA1 of the substrate 110 and electrically contactsthe first electrode 116. The first electrode 116 has the advantage ofbeing made of a transparent conductive material and transmitting emittedlight therethrough, but also has the disadvantage that it has very highelectrical resistance compared to opaque metals. Accordingly, in thefabrication of a large-area lighting apparatus 100, an electricalcurrent applied to a wide lighting area may not be uniformly distributeddue to the high resistance of the transparent conductive material, andthis non-uniform current distribution makes it impossible for thelarge-area lighting apparatus 100 to emit light with uniform brightness.

The auxiliary electrode 111 is positioned across the entire lightingarea EA, in the shape of a matrix form of thin lines, a mesh, a hexagon,an octagon, or a circle so that an electric current is evenly applied tothe first electrode 116 over the entire lighting area EA, thus enablingthe large-area lighting apparatus 100 to emit light with uniformbrightness.

Although FIG. 3 illustrates an example where the auxiliary electrode 111is positioned below the first electrode 116 including the first contactelectrode 127, the present disclosure is not limited to this example,and the auxiliary electrode 111 may be positioned over the firstelectrode 116 including the first contact electrode 127. The auxiliaryelectrode 111 placed in the first contact area CA1 may be used as acurrent transfer path to the first electrode 116, and also may functionas a contact electrode that comes into contact with the outside andapplies an external current to the first electrode 116.

The auxiliary electrode 111 may be made of a metal with highconductivity, such as Al, Au, Cu, Ti, W, Mo, or an alloy thereof. Theauxiliary electrode 111 may have a two-layer structure of an upperauxiliary electrode 111 a and a lower auxiliary electrode 111 b, but thepresent disclosure is not limited to this structure, and the auxiliaryelectrode 111 may consist of a single layer.

The passivation layer 115 a may be stacked in the lighting area EA andthe second contact area CA2 of the substrate 110. Although FIG. 2illustrates that the passivation layer 115 a is in the shape of arectangular frame having a certain width, the present disclosure is notlimited to this shape.

The passivation layer 115 a in the lighting area EA may be formed tocover the auxiliary electrode 111 and the overlying first electrode 116,but the passivation layer 115 a is not formed at a portion of thelight-emission area where light is actually emitted. In particular, thepassivation layer 115 a in the lighting area EA reduces the differencein level (or step coverage) caused by the auxiliary electrode 111 as itsurrounds the auxiliary electrode 111, which allows for stable formationof various layers to be formed later, without separation.

The passivation layer 115 a may be made of an inorganic material such asSiO_(x) or SiN_(x). Alternatively, the passivation layer 115 a may bemade of an organic material such as photoacryl or be made of a pluralityof layers of inorganic and organic materials.

The lighting apparatus 100 using an organic light-emitting diodeaccording to an exemplary aspect of the present disclosure ischaracterized in that the organic emissive layer 130 and the secondelectrode 126 are positioned on the entire surface of the substrate 110where the first electrode 116 and the passivation layer 115 a areplaced.

That is, the lighting apparatus 100 using an organic light-emittingdiode according to an exemplary aspect of the present disclosure ischaracterized in that the organic emissive layer 130 and the secondelectrode 126 are deposited on the entire surface, without using an openmask, which is a separate, complicated tool, and then the organicemissive layer 130 in the lighting area EA and the contact areas CA1 andCA2 becomes separated (broken or cut) by laser ablation, and at the sametime, the contact hole 114 for a contact with the anode is formed.

In this case, the trench T is formed by removing the organic emissivelayer 130 and the second electrode 126 from the edge of the lightingarea EA of the substrate 110 by laser ablation. Hereupon, the surface ofthe first passivation layer 115 a may be exposed via the trench T.

Moreover, the contact hole 114 exposing the first contact electrode 127may be formed in the first contact area CA1 of the substrate 110 byremoving a certain part of the organic emissive layer 130 and the secondelectrode 126 by laser ablation.

As such, the first contact electrode 127 may be formed from the firstelectrode 116 or as an additional electrode (not shown), and the secondcontact electrode 128 may be formed from the metal film 170.

When using an open mask as in the conventional art, different open masksshould be used on the organic emissive layer 130 and the secondelectrode 126, respectively. This requires elaborate processes inmanufacturing masks and tools. Moreover, in roll-to-roll processing,continuous feeding is required on the roll-to-sheet in one-pass ratherthan in individual sheets. Thus, complicated line equipment is required,and it is difficult to achieve precision.

Accordingly, the present disclosure, without using open masks, mayreduce costs and simplify processes and equipment, making them adaptableto a variety of models without additional cost. Moreover, OLEDs may bepatterned using simple equipment, without using an open mask and othertools, which is useful for roll-to-roll manufacturing.

That is, the present disclosure allows for micro-pattern forming,without using complicated masks and tools, in roll-to-roll processing aswell as in glass processing. Conventionally, open masks of differentshapes have been manufactured and used for different types of products.On the other hand, when a laser process is used, all that has to be doneis to change design information and input the changed information to theequipment, without any alteration of open masks. This allows for easyadaptation to various types of products.

As described above, the organic emissive layer 130 is a white organicemissive layer, and may be made up of blue, red, and green emittinglayers or be made up of a blue emitting layer and a yellow-greenemitting layer stacked in tandem. Moreover, the organic emissive layer130 may include an electron injection layer and a hole injection layerthat respectively inject electrons and holes into the emitting layers,an electron transport layer and a hole transport layer that respectivelytransport the injected electrons and holes to the emitting layers, and acharge generating layer that generates electric charges such aselectrons and holes.

The second electrode 126 may be made of metal, such as Al, Mo, Cu, andAg, or an alloy such as MoTi.

The first electrode 116, the organic emissive layer 130, and the secondelectrode 126 in the lighting area EA constitute an organiclight-emitting diode. The first electrode 116 is the anode of theorganic light-emitting diode, and the second electrode 126 is thecathode. When an electrical current is applied to the first electrode116 and the second electrode 126, electrons are injected into theorganic emissive layer 130 from the second electrode 126, and holes areinjected into the organic emissive layer 130 from the first electrode116. Thereafter, an exciton is created in the organic emissive layer130, and the decay of the exciton results in generating light that isequivalent to the difference in energy between the lowest unoccupiedmolecular orbital and highest occupied molecular orbital (HOMO and LUMO)of the emissive layer, causing the light to radiate downward (towardsthe substrate 110 in the figure).

Since the passivation layer 115 a is positioned over the auxiliaryelectrode 111 in the lighting area EA, the organic emissive layer 130above the auxiliary electrode 111 does not come into direct contact withthe first electrode 116 and therefore the organic light-emitting diodeis not present on the auxiliary electrode 111. That is, the organiclight-emitting diode in the lighting area EA is formed only at a portionthe light-emission area between the auxiliary electrodes 111 that havethe shape of a matrix, for example.

As the above-described trench T is formed on the edge of the lightingarea EA of the substrate 110, the organic emissive layer 130 in thelighting area EA and the organic emissive layer 130 in the contact areasCA1 and CA2 may be separated from each other. In the present disclosure,since the organic emissive layer 130 in the lighting area EA and theorganic emissive layer 130 in the contact areas CA1 and CA2 areseparated by the trench T, moisture penetrating the outer region of theorganic emissive layer 130 may be prevented from spreading along theorganic emissive layer 130 into a portion of the lighting area EA fromwhich light is actually emitted. Moreover, in the present disclosure,the organic emissive layer 130 becomes separated by laser ablationwithout an additional open mask or a photolithography process, therebyavoiding an additional fabrication process and the resulting increase incost.

Likewise, the second electrode 126 in the lighting area EA and thesecond electrode 126 in the contact areas CA1 and CA2 are separated fromeach other by the above-described trench T because the second electrode126 is positioned over the organic emissive layer 130 in the lightingarea EA and contact areas CA1 and CA2.

An adhesive 118 such as PSA (pressure sensitive adhesive) is applied tothe lighting area EA and the second contact area CA2 of the substrate110 where the second electrode 126 is formed, and the metal film 170 ispositioned over the adhesive 118 so that the metal film 170 is attachedto the substrate 110 to seal the lighting apparatus 100.

Then, a given protective film 175 may be attached to the entire surfaceof the lighting area EA of the substrate 110, but not to the contactareas CA1 and CA2.

The adhesive 118 may be a light curing adhesive or a heat curingadhesive.

The adhesive 118 according to an exemplary aspect of the presentdisclosure contains conductive particles 160, and the metal film 170including the second contact electrode 128 is electrically connected tothe second electrode 126 by the conductive particles 160.

The conductive particles 160 may be nickel, carbon, solder balls, etc.

In this case, as described above, the contact hole 114 is formed in thefirst contact area CA1 of the substrate 110 by removing a portion of theorganic emissive layer 130 and the second electrode 126, and the firstcontact electrode 127 connected to the first electrode 116 may beexposed externally via the contact hole 114. The second contactelectrode 128 is formed from a portion of the metal film 170, and thesecond contact electrode 128 may be electrically connected to the secondelectrode 126 by conductive particles 160 in the adhesive 118. Thus, thefirst contact electrode 127 and the second contact electrode 128 areelectrically connected to an external power source to apply anelectrical current to the first electrode 116 and the second electrode126, respectively.

Moreover, as described above, in the present disclosure, the organicemissive layer 130 and the second electrode 126 are stacked on theentire surface of the substrate 110, and the trench T is formed by laserablation to separate the organic emissive layer 130, thereby preventingmoisture from penetrating and spreading into the organic emissive layer130 in the lighting area EA.

Moreover, the present disclosure allows for roll-to-roll manufacturingsince the substrate 110 is made of a flexible plastic film and theorganic emissive layer 130 and the second electrode 126 are deposited onthe entire surface. This enables rapid processes in manufacturing thelighting apparatus 100 and reducing the manufacturing costs.

FIG. 4 is a cross-sectional view exemplifying the concept ofroll-to-roll equipment for manufacturing a flexible lighting apparatusthat can be bent.

Referring to FIG. 4, the roll-to-roll equipment for manufacturing aflexible lighting apparatus includes a film feed roller 52 feeding aplastic film 10, a film recovery roller 54 recovering the plastic film10, and a guide roller 56 guiding the plastic film 10.

Moreover, the roll-to-roll equipment includes a mask feed roller 62feeding an open mask 60 (or metal mask), a mask recovery roller 64recovering the open mask 60, and an evaporator 80 depositing an organicmaterial or metal.

In the roll-to-roll equipment thus constructed, the plastic film 10 usedas a substrate for the lighting apparatus is fed from the film feedroller 52 to the evaporator 80, and at the same time, the open mask 60is fed from the mask feed roller 62 to the evaporator 80. With the openmask 60 positioned on the entire surface of the plastic film 10, theevaporator 80 is used to deposit an organic material or metal in somepart of the plastic film 10.

After the deposition, the open mask 60 is separated from the plasticfilm 10, and the plastic film 10 is recovered by the film recoveryroller 64 and the open mask 60 is recovered by the mask recovery roller64.

Using the roll-to-roll equipment with this structure, the plastic film10 is continuously fed by the film feed roller 62, thereby enablingrapid fabrication of the lighting apparatus in the continuous process.However, this roll-to-roll equipment has the following problems.

The roll-to-roll equipment may be used in forming a variety of metalpatterns—especially useful when forming the organic emissive layer, thesecond electrode, etc. This can be achieved easily by roll-to-rollmanufacturing because the organic emissive layer or the second electrodeis deposited across the entire area of the substrate, rather than beingpatterned by a photolithography process in a certain part of thesubstrate.

However, when an organic emissive layer is formed by depositing anorganic emissive material on the entire surface of the substrate by theroll-to-roll equipment, the side of the organic emissive layer depositedover the entire surface is formed at the same level as the side of thesubstrate, thus causing the organic emissive layer to be exposed to theoutside from the side of the lighting apparatus. The organic emissivematerial is susceptible to moisture and, when combined with moisture,degrades quickly, causing the moisture to spread easily. Accordingly,the organic emissive layer should be kept from being exposed externallyin the fabrication of the lighting apparatus, in order to prevent thelighting apparatus from becoming defective due to the spread of moisturethrough the externally exposed organic emissive layer.

Hence, as the open mask blocks the perimeter area of the substrate, theorganic emissive layer is not deposited in the perimeter area of thesubstrate when depositing the organic emissive material. Moreover, bysealing the perimeter area with a sealant or an adhesive, the side ofthe organic emissive layer is sealed, and this prevents the organicemissive layer from being exposed to the outside.

However, when forming an organic emissive layer using the open mask 60,as shown in FIG. 4, a system (a feed roll, guide roll, recovery roll,etc.) that feeds the plastic film 10 and a system that feeds the openmask 60 should be integrated as an inline system. This increases notonly the length of the process line but also the length of the open mask60. Moreover, the plastic film 10 and the open mask 60 should be fed insync, and also need to be aligned in a continuous process. In addition,the open mask 60 should be cleaned after use, which is difficult due tothe long length of the open mask 60.

In other words, although a roll-to-roll manufacturing process requiresthe use of an open mask to enable rapid fabrication of a lightingapparatus, the open mask makes it practically difficult to fabricate thelighting apparatus by using the roll-to-roll equipment.

On the other hand, in the present disclosure, a trench is formed byremoving the organic emissive layer from the edge of the lighting areaof the substrate by laser ablation. As such, the organic emissive layerbecomes separated by the trench, even when an organic emissive layer isdeposited across the entire area of the substrate and the side of theorganic emissive layer is therefore exposed to the outside, therebypreventing moisture from penetrating into the lighting area through theexposed organic emissive layer. Accordingly, a lighting apparatusaccording to the present disclosure can be fabricated without using anopen mask, and this simplifies the fabrication process of the lightingapparatus, making it useful especially in roll-to-roll manufacturing.

In what follows, a lighting apparatus according to an exemplary aspectof the present disclosure and a method of fabricating a lightingapparatus with a typical structure by roll-to-roll processing will bedescribed to explain the benefits of the fabrication process of alighting apparatus according to an exemplary aspect of the presentdisclosure.

FIG. 5 is a flowchart sequentially showing a method of fabricating alighting apparatus using an organic light-emitting diode according to anexemplary aspect of the present disclosure.

Referring to FIG. 5, firstly, an auxiliary electrode and a firstelectrode are formed on a substrate made of a flexible, transparentplastic film (S110), and then a passivation layer is formed by stackingand etching an inorganic material (S120). The auxiliary electrode, firstelectrode, and passivation layer may be formed by inside roll-to-rollequipment with a photolithographic process using a photoresist and aphotomask.

Subsequently, an organic emissive layer is formed by depositing anorganic emissive material on the entire surface of the substrate byusing the roll-to-roll equipment shown in FIG. 4 (S130). Since, in thepresent disclosure, an organic emissive material is deposited withoutusing an open mask, the roll-to-roll equipment shown in FIG. 4 does notrequire the use of an open mask, mask feed roller, and mask recoveryroller.

Afterwards, a second electrode is formed by depositing a metal on theentire surface of the substrate (S140).

Subsequently, using laser ablation, a trench is formed along the edge ofthe lighting area of the substrate by removing portions of the organicemissive layer and the second electrode by laser ablation, and at thesame time a contact hole exposing a portion of 0a first contactelectrode is formed in a first contact area (S150).

Afterwards, a metal film is attached for sealing using an adhesivecontaining conductive particles, and at the same time a second contactelectrode of a metal film is electrically connected to the secondelectrode through the conductive particles (S160). Then, a protectivefilm is attached to the entire surface of the lighting area of thesubstrate.

FIG. 6 is a flowchart sequentially showing a method of fabricating alighting apparatus using an organic light-emitting diode according to acomparative example.

Referring to FIG. 6, firstly, an auxiliary electrode and a firstelectrode are formed on a substrate made of a flexible, transparentplastic film (S10), and then a first passivation layer is formed bystacking and etching an inorganic material (S20).

Subsequently, a first open mask (metal mask) is placed on the entiresurface of the substrate, and then an organic emissive layer is formedby depositing an organic emissive material (S30 and S40).

Afterwards, the first open mask placed on the entire surface of thesubstrate is replaced with a new, second open mask, and then a metal isdeposited to form a second electrode (S50 and S60).

Subsequently, the second open mask placed on the entire surface of thesubstrate is replaced with a new, third open mask, and then second andthird passivation layers are formed (S70 and S80).

Afterwards, a metal film is attached with an adhesive, therebycompleting a lighting apparatus (S90).

As described above, the present disclosure requires no open mask whenfabricating a lighting apparatus by using roll-to-roll equipment. Thus,the step of placing an open mask and the step of replacing the open maskare not needed, unlike with the lighting apparatus according to thecomparative example. Therefore, the lighting apparatus according to anexemplary aspect of the present disclosure allows for rapid fabrication.

Moreover, in the case of the lighting apparatus according to thecomparative example, the open masks used in the previous process shouldbe cleaned after completion of the process on the plastic film on thefeed roller, before a plastic film is fed to the feed roller to resumethe process. By contrast, the fabrication of a lighting apparatusaccording to an exemplary aspect of the present disclosure does notrequire cleaning of open masks. Accordingly, no cleaning equipment isrequired when fabricating a lighting apparatus according to an exemplaryaspect of the present disclosure. This may reduce costs and preventenvironmental contamination caused by cleaning. Moreover, no cleaningprocess is required between two consecutive deposition processes,thereby making the fabrication even more rapid.

Additionally, the lighting apparatus according to the comparativeexample requires equipment for positioning an open mask in front of thesubstrate, whereas the exemplary aspect of the present disclosure doesnot require such equipment, thereby simplifying the manufacturingequipment and reducing costs.

FIGS. 7A to 7G are plan views sequentially showing a method offabricating the lighting apparatus using an organic light-emittingdiode, shown in FIG. 2, according to an exemplary aspect of the presentdisclosure;

FIG. 8 is an enlarged view of a portion of the lighting area of FIG. 7B;

FIGS. 9A to 9F are cross-sectional views sequentially showing a methodof fabricating the lighting apparatus using an organic light-emittingdiode, shown in FIG. 3, according to an exemplary aspect of the presentdisclosure;

While the fabrication method here is illustrated with reference to aprocess carried out on roll-to-roll equipment, the present disclosure isnot limited to the roll-to-roll equipment but may be applicable togeneral manufacturing equipment using a glass substrate.

First of all, referring to FIGS. 7A and 9A, a metal such as Al, Au, Cu,Ti, W, and Mo, or an alloy thereof is deposited on a substrate 110 whichis divided into a lighting area and contact areas, and then etched toform an auxiliary electrode 111 consisting of a single layer or aplurality of layers in the lighting area and the first contact area.

Although FIG. 9A illustrates an example where the auxiliary electrode111 is formed of a two-layer structure of an upper auxiliary electrode111 a and a lower auxiliary electrode 111 b, the present disclosure isnot limited to this example, as stated above.

The auxiliary electrode 111 may be positioned across the entire lightingarea EA, in the shape of a matrix form of thin lines (shown in FIG. 8),a mesh, a hexagon, an octagon, or a circle.

Afterwards, a transparent conductive material such as ITO or IZO isstacked on the entire substrate 110 and etched to form a first electrode116 and a first contact electrode 127 in the lighting area and the firstcontact area. In this case, the first electrode 116 may extend to thefirst contact area outside the lighting area and constitute the firstcontact electrode 127.

While FIGS. 7A and 9A illustrate an example where the auxiliaryelectrode 111 is formed below the first electrode 116 including thefirst contact electrode 127, the present disclosure is not limited tothis example, and the auxiliary electrode 111 may be formed over thefirst electrode 116 including the first contact electrode 127. Theauxiliary electrode 111 placed in the first contact area may be used asa current transfer path to the first electrode 116, and also mayfunction as a contact electrode that comes into contact with the outsideand applies an external current to the first electrode 116.

Subsequently, referring to FIGS. 7B and 9B, an inorganic material suchas SiN_(x) or SiO_(x) or an organic material such as photoacryl isstacked in the lighting area and the second contact area of thesubstrate 110. Afterwards, the inorganic material or organic material isetched to form a passivation layer 115 a on the top and side of theauxiliary electrode 111 in the lighting area and in a portion of thesecond contact area.

The passivation layer 115 a in the lighting area may be formed to coverthe auxiliary electrode 111 and the overlying first electrode 116, butthe passivation layer 115 a is not formed at a portion of thelight-emission area where light is actually emitted (although inpractice, referring to FIG. 8, the passivation layer 115 a may be formedin a matrix shape in the light-emission area to cover the auxiliaryelectrode 111 arranged in a matrix shape). In particular, thepassivation layer 115 a in the lighting area reduces the difference inlevel (or step coverage) caused by the auxiliary electrode 111 as itsurrounds the auxiliary electrode 111, which allows for stable formationof various layers that are to be formed later, without separation.Although FIG. 7B illustrates that the passivation layer 115 a is in theshape of a rectangular frame of a certain width, the present disclosureis not limited to this shape.

Subsequently, referring to FIGS. 7C, 7D, and 9C, an organic emissivelayer 130 and a second electrode 126 are formed by sequentiallydepositing an organic emissive material and a metal across the entiresurface of the substrate 110.

In this case, the organic emissive layer 130 is a white organic emissivelayer, and may be made up of blue, red, and green emitting layers or bemade up of a blue emitting layer and a yellow-green emitting layerstacked in tandem. Moreover, the organic emissive layer 130 may includean electron injection layer and a hole injection layer that respectivelyinject electrons and holes into the emitting layers, an electrontransport layer and a hole transport layer that respectively transportthe injected electrons and holes to the emitting layers, and a chargegenerating layer that generates electric charges such as electrons andholes.

The second electrode 126 may be made of metal, such as Al, Mo, Cu, andAg, or an alloy such as MoTi.

The first electrode 116, organic emissive layer 130, and secondelectrode 126 in the lighting area constitute an organic light-emittingdiode.

Since the passivation layer 115 a is positioned over the auxiliaryelectrode 111 in the lighting area, the organic emissive layer 130 abovethe auxiliary electrode 111 does not come into direct contact with thefirst electrode 116 and therefore the organic light-emitting diode isnot present on the auxiliary electrode 111. That is, the organiclight-emitting diode in the lighting area is formed only in thelight-emission area defined by the auxiliary electrode 111 that has theshape of a matrix, for example (see FIG. 8).

As such, in the lighting apparatus using an organic light-emitting diodeaccording to the exemplary aspect of the present disclosure, the organicemissive layer 130 and the second electrode 126 are deposited on theentire surface, without using an open mask, which is a separate,complicated tool, and this may reduce costs and simplify the processesand equipment, making them adaptable to a variety of models withoutadditional cost. Moreover, OLEDs may be patterned using simpleequipment, without using an open mask and other tools, which is usefulfor roll-to-roll manufacturing.

Subsequently, referring to FIGS. 7E and 9D, a trench T exposing thesurface of the passivation layer 115 a is formed along the edge of thelighting area of the substrate 110 by partially removing the organicemissive layer 130 and second electrode 126 which are deposited over theentire surface.

Additionally, using laser ablation, a contact hole 114 exposing thefirst contact electrode 127 may be formed by removing the organicemissive layer 130 and second electrode 126 in the first contact area ofthe substrate 110.

As the above-described trench T is formed on the edge of the lightingarea of the substrate 110, the organic emissive layer 130 in thelighting area and the organic emissive layer 130 in the contact areasmay be separated from each other. In the present disclosure, since theorganic emissive layer 130 in the lighting area and the organic emissivelayer 130 in the contact areas are separated by the trench T, moisturepenetrating the outer region of the organic emissive layer 130 may beprevented from spreading along the organic emissive layer 130 into thelighting area from which light is actually emitted. Moreover, in thepresent disclosure, the organic emissive layer 130 becomes separated bylaser ablation without addition of any open mask or photolithographyprocess, thereby avoiding an additional fabrication process and theresulting increase in cost.

Subsequently, referring to FIGS. 7F and 9E, an adhesive 118 made of alight curing adhesive material or a heat curing adhesive material isapplied over the substrate 110. Further, the metal film 170 ispositioned over the adhesive 118, and then the adhesive 118 is cured toattach the metal film 117.

The adhesive 118 and the metal film 170 used as a sealing means may beattached to the lighting area and second contact area of the substrate110 where the second electrode 126 is formed.

The adhesive 118 according to an exemplary aspect of the presentdisclosure contains conductive particles 160, and the metal film 170including the second contact electrode 128 is electrically connected tothe second electrode 126 by the conductive particles 160.

Afterwards, referring to FIGS. 7G and 9F, a given protective film 175may be attached to the entire surface of the lighting area of thesubstrate 110, but not to the contact areas, thereby completing thelighting apparatus.

As described above, in the first contact area of the substrate 110, thefirst contact electrode 127 connected to the first electrode 116 may beexposed externally via the contact hole 114. The second contactelectrode 128 is formed from a portion of the metal film 170, and at thesame time, may be electrically connected to the second electrode 126 bythe conductive particles 160 in the adhesive 118. Thus, the firstcontact electrode 127 and the second contact electrode 128 areelectrically connected to an external power source to apply anelectrical current to the first electrode 116 and the second electrode126, respectively.

In this case, although the protective film 175 according to an exemplaryaspect of the present disclosure is attached to the entire surface ofthe lighting area of the substrate 110, but not to the contact area, thepresent disclosure is not limited to this. In the present disclosure,instead of forming the protective film in the second contact area, anopen hole may be formed to expose part of the second contact electrode,which will be described in detail with respect to another exemplaryaspect of the present disclosure.

FIG. 10 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to another exemplary aspect ofthe present disclosure;

FIG. 11 is a schematic cross-section view of the lighting apparatususing an organic light-emitting diode according to another exemplaryaspect of the present disclosure, taken along line II-II′ of FIG. 10.

The lighting apparatus using an organic light-emitting diode accordingto another exemplary aspect of the present disclosure, shown in FIGS. 10and 11, have substantially the same components as the lighting apparatususing an organic light-emitting diode according to the foregoingexemplary aspect of the present disclosure, except for the protectivefilm.

That is, a lighting apparatus using an organic light-emitting diodeaccording to another exemplary aspect of the present disclosure mayinclude an organic light-emitting diode part where surface emissionoccurs, and a sealing part that seals the organic light-emitting diodepart.

The organic light-emitting diode part is made up of organiclight-emitting diodes placed on the substrate. Referring to FIGS. 10 and11, the substrate 210 may be divided into a lighting area EA thatactually emits light and sends it out, and contact areas CA1 and CA2that are electrically connected externally via contact electrodes 227and 228 and apply signals to the lighting area EA.

The contact areas CA1 and CA2 may be electrically connected externallyvia the contact electrodes 227 and 228 as they are not covered by ametal film 270, used as a sealing means, and/or a protective film 275.The first contact electrode 227 is electrically connected externally asit is exposed via a contact hole 214, and the second contact electrode228, formed from a portion of the metal film 270, may be electricallyconnected externally as it is exposed via an open hole H formed in theprotective film 275.

The contact areas CA1 and CA2 may be located outside the lighting areaEA. For example, referring to FIG. 10, the contact areas CA1 and CA2 arelocated outside the upper part of the lighting area EA—that is, thefirst contact area CA1 may be located on the left side, and the secondcontact area CA2 may be located on the right side. This makes the moduleprocess easy. However, the present disclosure is not limited to thisconfiguration. The metal film 270 may be attached to the entire surfaceof the lighting area EA and second contact area CA2 of the substrate210, but not to the first contact area CA1, and the protective film 275may be attached to the entire surface of the lighting area EA of thesubstrate 110 and the second contact area CA2, but not to the firstcontact area CA1 and the open hole H.

An organic light-emitting diode is formed by a first electrode 216 and asecond electrode 226 positioned on the substrate 210 and an organicemissive layer 230 situated between the first and second electrodes 216and 226.

In this case, a trench T exposing a passivation layer 215 a may beformed along the edge of the lighting area EA by removing the organicemissive layer 230 and the second electrode 226. The trench T is formedin the shape of a closed curve along the edge of the lighting area EA,and functions to prevent moisture from penetrating the organic emissivelayer 230 in the lighting area EA.

Referring to FIG. 10, the trench T of this disclosure may be formed inthe shape of an overall rectangular frame, but the present disclosure isnot limited to this shape.

The trench T may separate (break or cut) the organic emissive layer 230along the edge of the lighting area EA, thereby preventing moisture fromspreading into the lighting area EA along the organic emissive layer230. In particular, the trench T of this disclosure may simplify theprocess by laser ablation without using any photolithography process.

In this case, the first electrode 216 including the first contactelectrode 227 is positioned on the substrate 210 made of transparentmaterial. The substrate 210, although may be made of hard material suchas glass, may be made of flexible material such as plastic to make thelighting apparatus 200 bendable. Moreover, the present disclosure allowsfor roll-to-roll processing by using a flexible plastic material as thesubstrate 210, thus enabling rapid fabrication of the lighting apparatus200.

The first electrode 216 including the first contact electrode 227 isformed in the lighting area EA and the first contact area CA1, and maybe made of transparent conductive material with a high work function.

The first electrode 216 may extend to the first contact area CA1 outsidethe lighting area EA and constitute the first contact electrode 227.

An auxiliary electrode 211 may be placed in the lighting area EA andfirst contact area CA1 of the substrate 210 and electrically connectedto the first electrode 216.

The auxiliary electrode 211 is positioned across the entire lightingarea EA, in the shape of a matrix of thin lines, a mesh, a hexagon, anoctagon, or a circle so that an electric current is evenly applied tothe first electrode 216 over the entire lighting area EA, thus enablingthe large-area lighting apparatus 200 to emit light with uniformbrightness.

Although FIG. 11 illustrates an example where the auxiliary electrode211 is positioned below the first electrode 216 including the firstcontact electrode 227, the present disclosure is not limited to thisexample, and the auxiliary electrode 211 may be positioned over thefirst electrode 216 including the first contact electrode 227. Theauxiliary electrode 211 placed in the first contact area CA1 may be usedas a current transfer path to the first electrode 216, and also mayfunction as a contact electrode that comes into contact with the outsideand applies an external current to the first electrode 216.

The auxiliary electrode 211 may be made of a metal with highconductivity, such as Al, Au, Cu, Ti, W, Mo, or an alloy thereof. Theauxiliary electrode 211 may have a two-layer structure of an upperauxiliary electrode 211 a and a lower auxiliary electrode 211 b, but thepresent disclosure is not limited to this structure, and the auxiliaryelectrode 211 may consist of a single layer.

The passivation layer 215 a may be stacked in the lighting area EA andsecond contact area CA2 of the substrate 210. Although FIG. 10illustrates that the passivation layer 215 a is in the shape of arectangular frame of a certain width, the present disclosure is notlimited to this shape.

The passivation layer 215 a in the lighting area EA is configured tocover the auxiliary electrode 211 and the overlying first electrode 216,but the passivation layer 215 a is not formed in the light-emission areawhere light is actually emitted. In particular, the passivation layer215 a in the lighting area EA reduces the difference in level caused bythe auxiliary electrode 211 as it surrounds the auxiliary electrode 211,which allows for stable formation of various layers that are to beformed later, without separation.

The passivation layer 215 a may be made of an inorganic material such asSiOx or SiNx. Alternatively, the passivation layer 215 a may be made ofan organic material such as photoacryl or be made of a plurality oflayers of inorganic and organic materials.

Like the foregoing exemplary aspect of the present disclosure, thelighting apparatus 200 using an organic light-emitting diode accordingto another exemplary aspect of the present disclosure is characterizedin that the organic emissive layer 230 and the second electrode 226 arepositioned on the entire surface of the substrate 210 where the firstelectrode 216 and the passivation layer 215 a are placed.

That is, the lighting apparatus 200 using an organic light-emittingdiode according to another exemplary aspect of the present disclosure ischaracterized in that the organic emissive layer 230 and the secondelectrode 226 are deposited on the entire surface, without using an openmask, which is a separate, complicated tool, and then the organicemissive layer 230 in the lighting area EA and contact areas CA1 and CA2becomes separated (broken or cut) by laser ablation, and at the sametime, the contact hole 214 for contact with the anode is formed.

In this case, the trench T is formed by removing the organic emissivelayer 230 and second electrode 226 from the edge of the lighting area EAof the substrate 210 by laser ablation. Hereupon, the surface of thefirst passivation layer 215 a may be exposed via the trench T.

Moreover, the contact hole 214 exposing the first contact electrode 227may be formed by removing a certain part of the organic emissive layer230 and second electrode 226 in the first contact area CA1 of thesubstrate 210 by laser ablation.

As such, the first contact electrode 227 may be formed from the firstelectrode 216 or as an additional electrode (not shown), and the secondcontact electrode 228 may be formed from the metal film 270.

As described above, the organic emissive layer 230 is a white organicemissive layer, and may be made up of blue, red, and green emittinglayers or be made up of a blue emitting layer and a yellow-greenemitting layer stacked in tandem. Moreover, the organic emissive layer230 may include an electron injection layer and a hole injection layerthat respectively inject electrons and holes into the emitting layers,an electron transport layer and a hole transport layer that respectivelytransport the injected electrons and holes to the emitting layers, and acharge generating layer that generates electric charges such aselectrons and holes.

The second electrode 226 may be made of metal, such as Al, Mo, Cu, andAg, or an alloy such as MoTi.

An adhesive 218 such as PSA (pressure sensitive adhesive) is applied tothe lighting area EA and second contact area CA2 of the substrate 210where the second electrode 226 is formed, and the metal film 270 ispositioned over the adhesive 218 so that the metal film 270 is attachedto the substrate 210 to seal the lighting apparatus 200.

Then, a given protective film 275 may be attached onto the metal film270. In another exemplary aspect of the present disclosure, instead offorming the protective film 275 in the second contact area CA2, an openhole H may be formed to expose part of the second contact electrode 228.In this case, the second contact electrode 228 is less exposedexternally compared to the foregoing exemplary aspect of the presentdisclosure, thereby minimizing external effects such as corrosion.

The adhesive 218 may be a light curing adhesive or a heat curingadhesive.

The adhesive 218 according to another exemplary aspect of the presentdisclosure contains conductive particles 260, and the metal film 270including the second contact electrode 228 is electrically connected tothe second electrode 226 by the conductive particles 260.

The conductive particles 260 may be nickel, carbon, solder balls, etc.

As described above, in the first contact area CA1 of the substrate 210,the first contact electrode 227 connected to the first electrode 216 maybe exposed externally via the contact hole 214. The second contactelectrode 228 may be formed from a portion of the metal film 270 andexposed externally via the open hole H, and the second contact electrode228 may be electrically connected to the second electrode 226 by theconductive particles 260 in the adhesive 218. Thus, the first contactelectrode 227 and the second contact electrode 228 are electricallyconnected to an external power source to apply an electrical current tothe first electrode 216 and the second electrode 226, respectively.

Moreover, as described above, in the present disclosure, the organicemissive layer 230 and the second electrode 226 are stacked on theentire surface of the substrate 210, and the trench T is formed by laserablation to separate the organic emissive layer 230, thereby preventingmoisture from penetrating and spreading into the organic emissive layer230 in the lighting area EA.

As described above, a given conductive layer may be formed in thecontact hole, and an electrical connection to the first contactelectrode may be made through the conductive layer, which will bedescribed in detail with respect to still another exemplary aspect ofthe present disclosure.

FIG. 12 is a plan view schematically showing a lighting apparatus usingan organic light-emitting diode according to still another exemplaryaspect of the present disclosure.

FIG. 13 is a schematic cross-section view of the lighting apparatususing an organic light-emitting diode according to still anotherexemplary aspect of the present disclosure, taken along line III-III′ ofFIG. 12.

The lighting apparatus using an organic light-emitting diode accordingto still another exemplary aspect of the present disclosure, shown inFIGS. 12 and 13, have substantially the same components as the lightingapparatus using an organic light-emitting diode according to theforegoing exemplary aspects of the present disclosure, except that aconductive layer is additionally formed in the first contact area.

That is, a lighting apparatus using an organic light-emitting diodeaccording to still another exemplary aspect of the present disclosuremay include an organic light-emitting diode part where surface emissionoccurs, and a sealing part that seals the organic light-emitting diodepart.

The organic light-emitting diode part is made up of organiclight-emitting diodes placed on the substrate. Referring to FIGS. 12 and13, the substrate 310 may be divided into a lighting area EA thatactually emits light and sends it out, and contact areas CA1 and CA2that are electrically connected externally via contact electrodes 327and 328 and apply signals to the lighting area EA. In still anotherexemplary aspect of the present disclosure, the first contact electrode327 may be electrically connected externally through a conductive film337 formed in a contact hole 314.

The contact areas CA1 and CA2 may be electrically connected externallyvia the contact electrodes 327 and 328 as they are not covered by ametal film 370, used as a sealing means, and/or a protective film 375.The first contact electrode 327 is electrically connected externally asit is connected to the overlying conductive film 338 via the contacthole 314, and the second contact electrode 328, formed from a portion ofthe metal film 370, may be exposed and electrically connectedexternally.

The contact areas CA1 and CA2 may be located outside the lighting areaEA. For example, referring to FIG. 12, the contact areas CA1 and CA2 arelocated outside the upper part of the lighting area EA—that is, thefirst contact area CA1 may be located on the left side, and the secondcontact area CA2 may be located on the right side. This makes the moduleprocess easy. However, the present disclosure is not limited to thisconfiguration. The metal film 370 may be attached to the entire surfaceof the lighting area EA and second contact area CA2 of the substrate310, but not to the first contact area CA1, and the protective film 375may be attached to the entire surface of the lighting area EA of thesubstrate 310, but not to the first and second contact areas CA1 andCA2.

An organic light-emitting diode is formed by a first electrode 316 and asecond electrode 326 positioned on the substrate 310 and an organicemissive layer 330 situated between the first and second electrodes 316and 326.

In this case, a trench T exposing a passivation layer 315 a may beformed along the edge of the lighting area EA by removing the organicemissive layer 330 and the second electrode 326. The trench T is formedin the shape of a closed curve along the edge of the lighting area EA,and functions to prevent moisture from penetrating the organic emissivelayer 330 in the lighting area EA.

Referring to FIG. 12, the trench T of this disclosure may be formed inthe shape of an overall rectangular frame, but the present disclosure isnot limited to this shape.

The trench T may separate (break or cut) the organic emissive layer 330along the edge of the lighting area EA, thereby preventing moisture fromspreading into the lighting area EA along the organic emissive layer330. In particular, the trench T of this disclosure may simplify theprocess by laser ablation without using any photolithography process.

In this case, the first electrode 316 including the first contactelectrode 327 is positioned on the substrate 310 made of transparentmaterial. The substrate 310, although may be made of hard material suchas glass, may be made of flexible material such as plastic to make thelighting apparatus 300 bendable. Moreover, the present disclosure allowsfor roll-to-roll processing by using a flexible plastic material as thesubstrate 310, thus enabling rapid fabrication of the lighting apparatus300

The first electrode 316 including the first contact electrode 327 isformed in the lighting area EA and the first contact area CA1, and maybe made of transparent conductive material with a high work function.

The first electrode 316 may extend to the first contact area CA1 outsidethe lighting area EA and constitute the first contact electrode 327.

An auxiliary electrode 311 may be placed in the lighting area EA andfirst contact area CA1 of the substrate 310 and electrically connectedto the first electrode 316.

The auxiliary electrode 311 is positioned across the entire lightingarea EA, in the shape of a matrix of thin lines, a mesh, a hexagon, anoctagon, or a circle so that an electric current is evenly applied tothe first electrode 316 over the entire lighting area EA, thus enablingthe large-area lighting apparatus 300 to emit light with uniformbrightness.

Although FIG. 13 illustrates an example where the auxiliary electrode311 is positioned below the first electrode 316 including the firstcontact electrode 327, the present disclosure is not limited to thisexample, and the auxiliary electrode 311 may be positioned over thefirst electrode 316 including the first contact electrode 327. Theauxiliary electrode 311 placed in the first contact area CA1 may be usedas a current transfer path to the first electrode 316, and also mayfunction as a contact electrode that comes into contact with the outsideand applies an external current to the first electrode 316.

The auxiliary electrode 311 may be made of a metal with highconductivity, such as Al, Au, Cu, Ti, W, Mo, or an alloy thereof. Theauxiliary electrode 311 may have a two-layer structure of an upperauxiliary electrode 311 a and a lower auxiliary electrode 311 b, but thepresent disclosure is not limited to this structure, and the auxiliaryelectrode 311 may consist of a single layer.

The passivation layer 315 a may be stacked in the lighting area EA andsecond contact area CA2 of the substrate 310. Although FIG. 12illustrates that the passivation layer 315 a is in the shape of arectangular frame of a certain width, the present disclosure is notlimited to this shape.

The passivation layer 315 a in the lighting area EA is configured tocover the auxiliary electrode 311 and the overlying first electrode 316,but the passivation layer 315 a is not formed in the light-emission areawhere light is actually emitted. In particular, the passivation layer315 a in the lighting area EA reduces the difference in level caused bythe auxiliary electrode 311 as it surrounds the auxiliary electrode 311,which allows for stable formation of various layers that are to beformed later, without separation.

The passivation layer 315 a may be made of an inorganic material such asSiO_(x) or SiN_(x). Alternatively, the passivation layer 315 a may bemade of an organic material such as photoacryl or be made of a pluralityof layers of inorganic and organic materials.

Like the foregoing exemplary aspects of the present disclosure, thelighting apparatus 300 using an organic light-emitting diode accordingto still another exemplary aspect of the present disclosure ischaracterized in that the organic emissive layer 330 and the secondelectrode 326 are positioned on the entire surface of the substrate 310where the first electrode 316 and the passivation layer 315 a areplaced.

That is, the lighting apparatus 300 using an organic light-emittingdiode according to still another exemplary aspect of the presentdisclosure is characterized in that the organic emissive layer 330 andthe second electrode 326 are deposited on the entire surface, withoutusing an open mask, which is a separate, complicated tool, and then theorganic emissive layer 330 in the lighting area EA and the contact areasCA1 and CA2 becomes separated (broken or cut) by laser ablation, and atthe same time, the contact hole 314 for contact with the anode isformed.

In this case, the trench T is formed by removing the organic emissivelayer 330 and second electrode 326 from the edge of the lighting area EAof the substrate 310 by laser ablation. Hereupon, the surface of thefirst passivation layer 315 a may be exposed via the trench T.

Moreover, the contact hole 314 exposing the first contact electrode 327may be formed by removing a certain part of the organic emissive layer330 and second electrode 326 in the first contact area CA1 of thesubstrate 310 by laser ablation.

As such, the first contact electrode 327 may be formed from the firstelectrode 316 or as an additional electrode (not shown), and the secondcontact electrode 328 may be formed from the metal film 370.

As described above, the organic emissive layer 330 is a white organicemissive layer, and may be made up of blue, red, and green emittinglayers or be made up of a blue emitting layer and a yellow-greenemitting layer stacked in tandem. Moreover, the organic emissive layer330 may include an electron injection layer and a hole injection layerthat respectively inject electrons and holes the emitting layers, anelectron transport layer and a hole transport layer that respectivelytransport the injected electrons and holes to the emitting layers, and acharge generating layer that generates electric charges such aselectrons and holes.

The second electrode 326 may be made of metal, such as Al, Mo, Cu, andAg, or an alloy such as MoTi.

An adhesive 318 such as PSA (pressure sensitive adhesive) is applied tothe lighting area EA and the second contact area CA2 of the substrate310 where the second electrode 326 is formed, and the metal film 370 ispositioned over the adhesive 318 so that the metal film 370 is attachedto the substrate 310 to seal the lighting apparatus 300.

Then, a protective film 375 may be attached onto the metal film 370.

The adhesive 318 may be a light curing adhesive or a heat curingadhesive.

The adhesive 318 according to still another exemplary aspect of thepresent disclosure contains conductive particles 360, and the metal film370 including the second contact electrode 328 is electrically connectedto the second electrode 326 by the conductive particles 360.

The conductive particles 360 may be nickel, carbon, solder balls, etc.

As described above, the conductive film 337 is formed in the firstcontact area CA1 of the substrate 310, and the conductive film 337 maybe electrically connected to the first contact electrode 327 via thecontact hole 314. The conductive film 337 may be formed in the contacthole 314 and over the second electrode 326 in the second contact areaCA2 by an Ag printing process, for example. However, the presentdisclosure is not limited to the aforementioned printing process, and avariety of methods such as a screen printing or an inject printing.

The second contact electrode 328 may be formed from a portion of themetal film 370 and exposed externally, and the second contact electrode328 may be electrically connected to the second electrode 326 by theconductive particles 360 in the adhesive 318. Thus, the first contactelectrode 327 and the second contact electrode 328 are electricallyconnected to an external power source to apply an electrical current tothe first electrode 316 and the second electrode 326, respectively.

Moreover, as described above, in the present disclosure, the organicemissive layer 330 and the second electrode 326 are stacked on theentire surface of the substrate 310, and the trench T is formed by laserablation to separate the organic emissive layer 330, thereby preventingmoisture from penetrating and spreading into the organic emissive layer330 in the lighting area EA.

Although the above description contains specific examples, these shouldnot be construed as limiting the scope of the disclosure, but as merelyproviding illustrations of the aspects of this disclosure. Therefore,the scope of the disclosure is defined not by the detailed description,but by the claims and their equivalents.

What is claimed is:
 1. A lighting apparatus using an organiclight-emitting diode, comprising: a substrate having a lighting area andfirst and second contact areas; a first electrode on the substrate; apassivation layer on the first electrode; an organic emissive layer onthe passivation layer; and a second electrode on the organic emissivelayer; wherein the passivation layer is exposed in the shape of a closedcurve along the edge of the lighting area.
 2. The lighting apparatus ofclaim 1, further comprising a first contact electrode disposed in thefirst contact area and extended from the first electrode in the lightingarea.
 3. The lighting apparatus of claim 2, further comprising a contacthole exposing the first contact electrode.
 4. The lighting apparatus ofclaim 3, further comprising a conductive film in the contact hole in thefirst contact area, and electrically contacts the first contactelectrode via the contact hole.
 5. The lighting apparatus of claim 1,further comprising an auxiliary electrode disposed in the lighting areaand the first contact area of the substrate, and electrically contactingthe first electrode.
 6. The lighting apparatus of claim 5, wherein thepassivation layer is disposed over the auxiliary electrode.
 7. Alighting apparatus using an organic light-emitting diode, comprising: asubstrate having a lighting area and first and second contact areas; afirst electrode on the substrate; a passivation layer on the firstelectrode; an organic emissive layer on the passivation layer; a secondelectrode on the organic emissive layer; an adhesive containingconductive particles, disposed on the lighting area and the secondcontact area of the substrate where the second electrode is formed; anda metal film positioned over the adhesive so that the metal film isattached to the substrate; wherein the second electrode in the lightingarea and the contact areas are separated from each other, and the metalfilm is electrically connected to the second electrode through theconductive particles.
 8. The lighting apparatus of claim 7, furthercomprising a second contact electrode disposed in the second contactarea and extended from the metal film in the lighting area.
 9. Thelighting apparatus of claim 8, further comprising a protective filmdisposed on the metal film in the lighting area.
 10. The lightingapparatus of claim 9, wherein the protective film has an open holeexposing the second contact electrode.